Medical catheter assembly including multi-piece connector

ABSTRACT

A medical catheter assembly including a multi-piece connector. In one embodiment, the medical catheter assembly is a PEG implanting assembly comprising a tubular dilator and a silicone feeding tube having an internal bolster at its rear end. The assembly also comprises a multi-piece connector comprising an inner ring, a fitting and an outer ring. The inner ring has an outer diameter greater than the inner diameter of the feeding tube and is coaxially disposed within the feeding tube by a friction-fit. The fitting comprises a front portion, an intermediate portion and a rear portion, the intermediate portion including a shoulder having an outer diameter greater than the inner diameter of the feeding tube. The front portion of the fitting is inserted through the rear end of the dilator and is secured to the dilator by a plurality of barbs. The shoulder and the rear portion of the fitting are inserted into the feeding tube through its rear end, with the rear portion of the fitting being inserted into the inner ring and secured thereto by mating threads. The outer ring is inserted over the feeding tube and is positioned between the shoulder and the inner ring, the outer ring being sized to securely retain the feeding tube between the outer ring and the inner ring and between the outer ring and the shoulder.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/440,009, filed May 16, 2003, now U.S. Pat. No. 7,507,230,which in turn is a continuation-in-part of U.S. patent application Ser.No. 10/078,223, filed Feb. 19, 2002, now U.S. Pat. No. 6,802,836, bothof which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to medical catheters, such asgastrostomy feeding tubes, and relates more particularly to medicalcatheter assemblies, such as percutaneous endoscopic gastrostomy (PEG)implanting assemblies.

Certain patients are unable to take food and/or medications transorallydue to an inability to swallow. Such an inability to swallow may be dueto a variety of reasons, such as esophageal cancer, neurologicalimpairment and the like. Although the intravenous administration of foodand/or medications to such patients may be a viable short-term approach,it is not well-suited for the long-term. Accordingly, the most commonapproach to the long-term feeding of such patients involves gastrostomy,i.e., the creation of a feeding tract or stoma between the stomach andthe upper abdominal wall. Feeding is then typically performed byadministering food through a catheter or feeding tube that has beeninserted into the feeding tract, with the distal end of the feeding tubeextending into the stomach and being retained therein by an internalanchor or bolster and the proximal end of the feeding tube extendingthrough the abdominal wall.

Although gastrostomies were first performed surgically, mostgastrostomies are now performed using percutaneous endoscopy and resultin the implantation of a catheter/bolster assembly (also commonlyreferred to as a percutaneous endoscopic gastrostomy (PEG) device) inthe patient. Two of the more common techniques for implanting a PEGdevice in a patient are “the push method” (also known as “the Sacks-Vinemethod”) and “the pull method” (also known as “the Gauderer-Ponskymethod”). Information regarding the foregoing two methods may be foundin the following patents, all of which are incorporated herein byreference: U.S. Pat. No. 5,391,159, inventors Hirsch et al., whichissued Feb. 21, 1995; U.S. Pat. No. 5,167,627, inventors Clegg et al.,which issued Dec. 1, 1992; U.S. Pat. No. 5,112,310, inventor Grobe,which issued May 12, 1992; U.S. Pat. No. 4,900,306, inventors Quinn etal., which issued Feb. 13, 1990; and U.S. Pat. No. 4,861,334, inventorNawaz, which issued Aug. 29, 1989.

According to the push method, the distal end of an endoscope is insertedinto a patient's mouth and is passed through the esophagus into thestomach. After distension of the stomach by inflation, an entry site onthe abdomen is identified, and an incision is made by passing a needlewith an outer cannula (e.g., a Seldinger needle) through the abdominalwall and into the stomach. The needle is then removed while keeping thecannula in place. Next, a snare is inserted into the stomach via theendoscope and is looped over the distal end of the cannula. A first endof a flexible guidewire is then passed through the cannula and into thestomach where it is grasped by the snare, the second end of theguidewire remaining external to the patient. The endoscope and the snareare then withdrawn from the mouth of the patient to deliver the firstend of the guidewire.

A push-type catheter implanting assembly is then inserted over the firstend of the guidewire and is pushed over the guidewire towards its secondend. The push-type catheter implanting assembly typically comprises agastrostomy feeding tube, the gastrostomy feeding tube having adome-shaped internal bolster disposed at its trailing end and having atubular dilator serially connected to its leading end. The gastrostomyfeeding tube and the internal bolster are typically made of a soft,biocompatible material, like silicone rubber, and may form a unitarystructure. The dilator, which tapers in outer diameter from its trailingend to its leading end, is typically made of polyethylene or a likematerial which is stiffer than silicone but which still possesses someflexibility. Advancement of the push-type catheter implanting assemblyover the guidewire continues until the front end of the dilator reachesthe cannula and pushes the cannula out through the abdominal wall of thepatient. The front end of the dilator is then pulled through theabdominal wall until the front end of the gastrostomy feeding tubeemerges from the abdomen and, thereafter, the internal bolster at therear end of the gastrostomy feeding tube engages the gastric wall.

With the internal bolster in place against the gastric wall, a proximalportion of the implanted gastrostomy feeding tube is then typically cutand removed from the implanted tube to reduce the externally-extendingportion of the tube to a desired length. (The removal of the proximalportion of the gastrostomy feeding tube also results in the removal ofthe dilator, which is connected thereto.) An external bolster istypically secured to the remaining implanted portion of the feeding tubeto engage the abdomen in such a way as to prevent longitudinal movementof the feeding tube within the stoma tract. Additionally, a “Y-port”adapter is typically attached to the proximal end of the implantedfeeding tube, the Y-port adapter being adapted to receive a pair ofconnector tips through which food and/or medications may be dispensed.In addition, a detachable locking clip is typically secured to theimplanted feeding tube at a point between the external bolster and theY-port adapter to prevent gastric fluids from escaping through theproximal end of the feeding tube when the feeding tube is not in use.

As can readily be appreciated, because the leading end of thegastrostomy feeding tube is drawn through the abdomen by pulling on thedilator, the connection between the dilator and the gastrostomy feedingtube must be strong enough to withstand the tensile force appliedthereto. Otherwise, the gastrostomy feeding tube may separate from thedilator prior to emergence of the feeding tube from the patient, therebyrequiring the feeding tube to be retrieved from the patient and possiblyleading to undesired complications. For connections like theaforementioned connection between the gastrostomy feeding tube and thedilator of a push-type catheter implanting assembly, the industrystandard minimum tensile strength is 17 pounds (see BS EN 1615:2000).

Historically, however, this standard has not typically been met by theconventional type of connection used to couple a dilator to agastrostomy feeding tube. An example of such a connection typicallycomprises an appropriately dimensioned tubular fitting having barbs atopposite ends thereof. One end of the tubular fitting is inserted intothe trailing end of the dilator, and the opposite end of the fitting isinserted into the leading end of the gastrostomy feeding tube. Theconnection also comprises a short length of plastic tubing, which isshrink-wrapped around the trailing end of the dilator and the leadingend of the feeding tube (as well as surrounding the fitting disposedwithin the trailing end of the dilator and the leading end of thefeeding tube).

In addition to failing frequently to meet the minimum tensile strengthrequired for a connection between a dilator and a feeding tube, othershortcomings with the above-described connection are (i) that theapplication of the shrink-wrapped length of tubing to the assemblyrequires the expenditure of time and labor, (ii) that the shrink-wrappedtubing undesirably increases the cross-sectional profile of theassembly, and (iii) that there is a widespread perception that the endsof the shrink-wrapped tubing, which ends do not lie flush with thedilator or the feeding tube, may snag tissue as the assembly makes itswinding path through the patient.

According to the pull method, the distal end of an endoscope is insertedinto a patient's mouth and is passed through the esophagus into thestomach. After distension of the stomach by inflation, an entry site onthe abdomen is identified, and an incision is made by passing a needlewith an outer cannula (e.g., a Seldinger needle) through the abdominalwall and into the stomach. The needle is then removed while keeping thecannula in place. Next, a snare is inserted into the stomach via theendoscope and is looped over the distal end of the cannula. A first endof a suture is then passed through the cannula and into the stomachwhere it is grasped by the snare, the second end of the suture remainingexternal to the patient. The endoscope and the snare are then withdrawnfrom the mouth of the patient to deliver the first end of the suture.The first end of the suture is then coupled to the leading end of apull-type catheter implanting assembly, the pull-type catheterimplanting assembly comprising a gastrostomy feeding tube having aninternal bolster at its trailing end and a plastic fitting at itsleading end. The plastic fitting has a barbed rear portion mountedwithin the leading end of the feeding tube and a conical front portionthat serves as a dilator, said conical front portion tapering indiameter from the leading end of the feeding tube to a front tip. A wireloop is fixed to the front tip of the plastic fitting, the first end ofthe suture being tied to the wire loop.

Using the second end of the suture, the pull-type catheter implantingassembly is then pulled retrograde through the patient until thegastrostomy feeding tube emerges from the abdomen of the patient and theinternal bolster engages the gastric wall of the patient. Next, as isthe case in the push method, the implanted gastrostomy feeding tube istypically cut to a desired length, an external bolster is typicallysecured to the cut implanted tube, a “Y-port” adapter is typicallyattached to the proximal end of the implanted feeding tube, and adetachable locking clip is typically secured to the implanted feedingtube at a point between the external bolster and the Y-port adapter.

As can readily be appreciated, because the pull-type catheter assemblyis moved into position within the patient's body by pulling on thesuture, it is very important that the plastic fitting maintain itscoupling to the gastrostomy feeding tube.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a novel medicalcatheter assembly.

It is another object of the present invention to provide a medicalcatheter assembly as described above that overcomes at least some of theproblems described above in connection with existing medical catheterassemblies of the type used to implant PEG devices.

The present invention is based, at least in part, on the presentinventors' recognition that certain existing PEG-implanting assembliesfail to withstand the considerable separation force that is appliedduring implantation. This failure is largely attributable to the factthat a strong connection cannot be maintained between a gastrostomyfeeding tube, which is typically made of silicone rubber, and a(push-type or pull-type) dilator, which is typically not made ofsilicone rubber, but rather, is typically made of a thermoplasticmaterial.

Therefore, according to one aspect of the invention, there is provided amedical catheter assembly, said medical catheter assembly comprising (a)a medical catheter, said medical catheter being made of an elasticmaterial and having a front end, a rear end and an inner diameter; (b) afirst tubular member, said first tubular member having an outer diametergreater than the inner diameter of said medical catheter, said firsttubular member being coaxially disposed within said medical catheter andsecured thereto by a friction-fit; (c) a fitting, said fittingcomprising a shoulder and a rear portion, said shoulder being positionedin front of said rear portion and having an outer diameter greater thanthe inner diameter of said medical catheter, said shoulder and said rearportion being inserted into said medical catheter through said frontend, with said rear portion inserted into said first tubular member andsecured thereto; and (d) a second tubular member, said second tubularmember being inserted over said medical catheter and positioned betweensaid shoulder and said first tubular member, said second tubular memberbeing appropriately sized to securely retain said medical catheterbetween said second tubular member and said first tubular member and tosecurely retain said medical catheter between said second tubular memberand said shoulder.

In one embodiment, the aforementioned medical catheter assembly is apull-type PEG implanting assembly. In such an embodiment, the fittingpreferably further comprises a front portion in front of said shoulder,said front portion extending beyond said front end of said medicalcatheter, said front portion being conical in shape and coming to a tipat a front end of said fitting. A wire loop is preferably secured tosaid fitting, for example by insert-molding, and extends forwardly fromthe front end of said fitting.

In another embodiment, the above-described medical catheter assembly isa push-type PEG implanting assembly. In such an embodiment, the assemblypreferably further comprises a tubular dilator, and the fittingpreferably further comprises a front portion in front of said shoulder,said front portion extending beyond said front end of said medicalcatheter and being secured within the rear end of the tubular dilator,for example by barbs formed on said fitting engageable with the innersurface of said dilator. The fitting is preferably further provided witha longitudinal bore through which a guidewire may be passed.

In both the pull-type and push-type PEG implanting assemblies describedabove, the rear portion of the fitting may be secured to the firsttubular member in a variety of different ways. For example, the fittingrear portion and the first tubular member may be joined together by themating engagement of threads, one such thread being provided on theinterior surface of the first tubular member and the other thread beingprovided on the exterior surface of the fitting rear portion.Alternatively, the fitting rear portion may be shaped to include a pairof resilient legs having outwardly-facing, opposing feet, and the firsttubular member may be shaped to include transverse openings adapted toreceive the outwardly-facing, opposing feet. Alternatively, the fittingrear portion and the first tubular member may be joined together byspin-welding. Alternatively, the fitting rear portion and the firsttubular member may be complementarily shaped to permit being joined in apush-twist-pull fashion.

The present invention is also directed to a medical catheter assembly,said medical catheter assembly comprising (a) a medical catheter; (b) afirst tubular member, said first tubular member being secured withinsaid medical catheter; and (c) a fitting, said fitting comprising a rearportion, said rear portion being positioned within said first tubularmember and secured thereto.

The present invention is additionally directed to a connector forconnecting a first length of tubing to a second length of tubing, thefirst length of tubing being made of an elastic material, said connectorcomprising (a) a first tubular member, said first tubular member havingan outer diameter greater than the inner diameter of said first lengthof tubing, said first tubular member being adapted to be coaxiallyinserted into said first length of tubing and secured therewithin by afriction-fit; (b) a fitting, said fitting comprising a front portion, ashoulder and a rear portion, said shoulder being positioned between saidfront portion and said rear portion and having an outer diameter greaterthan the inner diameter of said first length of tubing, said shoulderand said rear portion being adapted to be coaxially inserted into saidfirst length of tubing, said rear portion of said fitting being adaptedto be coaxially inserted into said first tubular member and securedthereto, said front portion of said fitting being adapted to becoaxially inserted into said second length of tubing and securedthereto; and (c) a second tubular member, said second tubular memberbeing adapted to be inserted over said first length of tubing andpositioned between said shoulder and said first tubular member, saidsecond tubular member being appropriately sized so that, with saidfitting and said first tubular member secured to one another, said firstlength of tubing may be securely retained between said second tubularmember and said first tubular member and between said second tubularmember and said shoulder.

The present invention is further directed to a connector for use with afirst length of tubing, the first length of tubing being made of anelastic material, said connector comprising (a) a first tubular member,said first tubular member having an outer diameter greater than theinner diameter of said first length of tubing, said first tubular memberbeing adapted to be coaxially inserted into said first length of tubingand secured therewithin by a friction-fit; (b) a fitting, said fittingcomprising a front portion, a shoulder and a rear portion, said shoulderbeing positioned between said front portion and said rear portion andhaving an outer diameter greater than the inner diameter of said firstlength of tubing, said shoulder and said rear portion being adapted tobe coaxially inserted into said first length of tubing, with said rearportion of said fitting being adapted to be coaxially inserted into saidfirst tubular member and secured thereto, said front portion of saidfitting being conical in shape and terminating in a tip at a front endthereof; (c) a wire loop extending forwardly from said front end of saidfitting; and (d) a second tubular member, said second tubular memberbeing adapted to be inserted over said first length of tubing andpositioned between said shoulder and said first tubular member, saidsecond tubular member being appropriately sized so that, with saidfitting and said first tubular member secured to one another, said firstlength of tubing may be securely retained between said second tubularmember and said first tubular member and between said second tubularmember and said shoulder.

For purposes of the present specification and claims, various relationalterms like “top,” “bottom,” “upper,” “lower,” “front,” and “rear” areused to describe the present invention when said invention is positionedin or viewed from a given orientation. It is to be understood that, byaltering the orientation of the invention, certain relational terms mayneed to be adjusted accordingly.

Additional objects, as well as features and advantages, of the presentinvention will be set forth in part in the description which follows,and in part will be obvious from the description or may be learned bypractice of the invention. In the description, reference is made to theaccompanying drawings which form a part thereof and in which is shown,by way of illustration, various embodiments for practicing theinvention. The embodiments will be described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the invention.The following detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present invention is best definedby the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are hereby incorporated into andconstitute a part of this specification, illustrate various embodimentsof the invention and, together with the description, serve to explainthe principles of the invention. In the drawings wherein like referencenumerals represent like parts:

FIG. 1 is a fragmentary, perspective view of a conventional medicalcatheter assembly adapted for percutaneous endoscopic implantation in apatient using the push method;

FIG. 2 is a fragmentary, exploded, perspective view of the conventionalmedical catheter assembly of FIG. 1 prior to the heat-shrinking of theshort plastic tubing;

FIG. 3 is a fragmentary, partially exploded, perspective view of aconventional medical catheter assembly adapted for percutaneousendoscopic implantation in a patient using the pull method;

FIG. 4 is a fragmentary, longitudinal section view of a first embodimentof a medical catheter assembly constructed according to teachings of thepresent invention, said medical catheter assembly being adapted forpercutaneous endoscopic use in a patient using the push method;

FIG. 5 is a fragmentary, exploded, perspective view of the medicalcatheter assembly of FIG. 4;

FIGS. 6( a) through 6(c) are enlarged perspective, section, and sideviews, respectively, of the fitting shown in FIG. 4;

FIGS. 7( a) through 7(c) are enlarged side, end, and section views,respectively, of the inner ring member shown in FIG. 4;

FIGS. 8( a) and 8(b) are enlarged end and section views, respectively,of the outer ring member shown in FIG. 4;

FIG. 9 is a fragmentary, longitudinal section view of a secondembodiment of a medical catheter assembly constructed according toteachings of the present invention, said medical catheter assembly beingadapted for percutaneous endoscopic use in a patient using the pushmethod;

FIGS. 10( a) and 10(b) are perspective and side views, respectively, ofthe fitting shown in FIG. 9;

FIGS. 11( a) and 11(b) are perspective and side views, respectively, ofthe inner ring shown in FIG. 9;

FIG. 12( a) is a fragmentary, longitudinal section view of a thirdembodiment of a medical catheter assembly constructed according toteachings of the present invention, said medical catheter assembly beingadapted for percutaneous endoscopic use in a patient using the pushmethod;

FIG. 12( b) is a transverse section view of the medical catheterassembly of FIG. 12( a), illustrating the locking together of thefitting and the inner ring;

FIGS. 13( a) and 13(b) are perspective and side views, respectively, ofthe fitting shown in FIG. 12( a);

FIG. 14 is a perspective view of the inner ring shown in FIG. 12( a);

FIG. 15 is a fragmentary, longitudinal section view of a fourthembodiment of a medical catheter assembly constructed according toteachings of the present invention, said medical catheter assembly beingadapted for percutaneous endoscopic use in a patient using the pullmethod; and

FIG. 16 is a partially exploded, perspective view of the medicalcatheter assembly shown in FIG. 15.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIGS. 1 and 2, there are shown fragmentary, perspectiveand fragmentary, exploded, perspective views, respectively, of aconventional medical catheter assembly adapted for percutaneousendoscopic implantation in a patient using the push method, saidconventional medical catheter assembly being represented generally byreference numeral 11.

Assembly 11, which is shown prior to use on a patient, comprises agastrostomy feeding tube 13, an internal bolster 14, a dilator 15, afitting 17 and a short length of tubing 19.

Tube 13, which is made of a soft, biocompatible, silicone rubber, is anelongated, tubular member having a trailing end 25 and a leading end 27.A series of ruler markings (not shown) are printed on tube 13 and extendseveral inches from trailing end 25 in the direction of leading end 27to facilitate the cutting of tube 13 to a desired length after it hasbeen implanted in a patient.

Internal bolster 14, which is also made of a soft, biocompatible,silicone rubber, is securely disposed at trailing end 25 of tube 13 and,in the present embodiment, forms a unitary structure therewith.

Dilator 15, which is made of a polyethylene having sufficient rigidityto open a stoma and sufficient flexibility to permit its being bentthrough a patient, is a tubular member having a leading end 31 and atrailing end 33. Dilator 15 is dimensioned to gradually increase indiameter over a length of several inches from leading end 31, which issized to conform closely to a guidewire inserted thereinto, to trailingend 33, which is sized to approximate the dimensions of leading end 27of tube 13.

Fitting 17, which is made of a rigid plastic, is a unitary tubularmember having a front portion 40 and a rear portion 42, front portion 40beginning with a leading end 41, rear portion 42 terminating in atrailing end 43. Front portion 40 is inserted into dilator 15 throughtrailing end 33 and is secured within dilator 15 by a series of externalbarbs 45 extending rearwardly from leading end 41. Rear portion 42 isinserted into gastrostomy feeding tube 13 through leading end 27 and issecured within tube 13 by a series of external barbs 47 extendingforwardly from trailing end 43.

Tubing 19, which is a unitary member made of a heat-shrinkable material,is shaped to include a leading end 51 inserted over trailing end 33 ofdilator 15 (as well as over leading end 41 of fitting 17) and a trailingend 53 inserted over leading end 27 of tube 13 (as well as over trailingend 43 of fitting 17). As can be seen in FIG. 1, because tubing 19 istightly fitted over tube 13, dilator 15, and fitting 17, tubing 19 helpsto soften the transition of outer dimensions among the variouscomponents.

However, as noted above, despite the reinforcement to the connectionprovided by tubing 19, assembly 11 often fails to withstand tensileforces in the range of about 17 pounds and, therefore, does not meetindustry standards, such as BS EN 1615:2000. In addition, theapplication of tubing 19 to its underlying components adds time andlabor and, therefore, expense to the manufacture of assembly 11.Furthermore, tubing 19 adds to the cross-sectional profile of assembly11, and there is a widespread perception in the industry that ends 51and 53 of tubing 19, which do not lie flush with dilator 15 or feedingtube 13, may snag tissue as assembly 11 winds its way through a patient.

Referring now to FIG. 3, there is shown a fragmentary, partiallyexploded, perspective view of a conventional medical catheter assemblyadapted for percutaneous endoscopic implantation in a patient using thepull method, said conventional medical catheter assembly beingrepresented generally by reference numeral 71.

Assembly 71, which is shown prior to use on a patient, comprises agastrostomy feeding tube 73, an internal bolster 74 and a fittingassembly 75.

Tube 73 and bolster 74 are indistinguishable in size, shape andcomposition from tube 13 and bolster 14, respectively, of assembly 11.

Fitting assembly 75 comprises a fitting 85. Fitting 85, which is made ofa rigid plastic, is shaped to include a barbed rear portion 87 mountedwithin leading end 81 of tube 73 and a conical front portion 89 thatserves as a dilator, front portion 89 tapering in diameter from a pointproximate to leading end 81 of tube 73 to a front tip 91. A wire loop93, which is adapted to be secured to the first end of a suture, isfixed (typically by insert-molding) to front tip 91.

Unfortunately, as noted above, assembly 71 often fails to withstandtensile forces in the range of about 17 pounds, with fitting 85frequently being pulled out of tube 73.

Referring now to FIGS. 4 and 5, there are shown fragmentary section andfragmentary exploded perspective views, respectively, of a firstembodiment of a medical catheter assembly constructed according toteachings of the present invention and adapted for percutaneousendoscopic implantation in a patient using the push method, said medicalcatheter assembly being represented generally by reference numeral 101.

Assembly 101 comprises a gastrostomy feeding tube 103 and an internalbolster 104. Tube 103, which is similar to tube 13 of assembly 11, is anelongated, tubular member made of a soft, biocompatible, elasticmaterial, such as a silicone rubber, and is shaped to include a trailingend 105 and a leading end 107. Although not wishing to be limited to anyparticular dimensions, tube 103 may have a length of about 2 feet and adiameter of 18 Fr., 20 Fr. or 24 Fr. A series of ruler markings (notshown) are printed on tube 103 and extend several inches from trailingend 105 in the direction of leading end 107 to facilitate the cutting oftube 103 to a desired length after it has been implanted in a patient.

Internal bolster 104, which is made of a soft, biocompatible, material,such as a silicone rubber, is securely disposed at trailing end 105 oftube 103 and, in the present embodiment, forms a unitary structuretherewith.

Assembly 101 also comprises a dilator 108, dilator 108 being a unitarytubular member having a leading end 109 and a trailing end 111. Dilator108 is made of a polyethylene having sufficient rigidity to open a stomaand, at the same time, sufficient flexibility to permit its being bentthrough a patient. Dilator 108 is dimensioned to gradually increase indiameter over a length of several inches from leading end 109, which issized to conform closely to a guidewire inserted thereinto, toapproximately the diameter of tube 103. Leading end 107 of tube 103 isinserted into dilator 108 through trailing end 111, trailing end 111being outwardly flared, for example, by a flaring iron, to facilitatereceiving leading end 107 of tube 103.

Assembly 101 additionally comprises a fitting 121 (shown separately inFIGS. 6( a) through 6(c)), fitting 121 being a unitary tubular memberpreferably made of a rigid material, such as a rigid molded plastic.Fitting 121 is shaped to include a front portion 122-1, an intermediateportion 122-2 and a rear portion 122-3, front portion 122-1 terminatingin a leading end 123, rear portion 122-3 terminating in a trailing end125. A longitudinal bore 126 extends the length of fitting 121, bore 126being outwardly flared at its front end. Longitudinal bore 126 isappropriately sized to receive a guidewire therethrough. In this manner,assembly 101 may be advanced through a patient over said guidewire usingthe push method.

Leading end 123 of fitting 121 is coaxially inserted into dilator 108through trailing end 111 and is secured within dilator 108 by a seriesof external barbs 127 formed on front portion 122-1. Trailing end 125 offitting 121 is coaxially inserted into gastrostomy feeding tube 103through leading end 107. An external helical thread 129, whose purposewill be discussed below, is integrally formed on rear portion 122-3 andextends from trailing end 125 to intermediate portion 122-2.

Intermediate portion 122-2 is shaped to include an external annularflange or shoulder 131, the purpose of shoulder 131 being discussedbelow.

Assembly 101 further comprises an inner ring 141 (shown separately inFIGS. 7( a) through 7(c)), inner ring 141 being a unitary tubular memberpreferably made of a rigid material, such as a rigid molded plastic, andhaving a leading end 143, a trailing end 145 and a longitudinal bore146. Inner ring 141 is coaxially positioned within tube 103 at a certaindepth, e.g., about 1.5 inches from leading end 107, and has an outerdiameter that is greater than the inner diameter of tube 103; as aresult, inner ring 141 is secured within tube 103 by a press-fit.

Longitudinal bore 146 of inner ring 141 is appropriately sized toreceive trailing end 125 of fitting 121 therewithin, and an internalhelical thread 147 is formed on the inner surface of inner ring 141 tomatingly engage external helical thread 129 so as to lock togetherfitting 121 and ring 141.

Assembly 101 further comprises an outer ring 151 (shown separately inFIGS. 8( a) and 8(b)), outer ring 151 being a unitary tubular memberpreferably made of a rigid material, such as a rigid molded plastic, andhaving a leading end 153, a trailing end 155 and a longitudinal bore157. Outer ring 151 coaxially surrounds tube 103 between shoulder 131and inner ring 141 and has an inner diameter that is both slightlygreater than trailing end 125 of fitting 121 and less than the outerdiameters of shoulder 131 and inner ring 141, respectively. In thismanner, with fitting 121 and ring 141 fully screwed together, tube 103becomes securely coupled to fitting 121 through a pair of pinch points,one such pinch point being between leading end 153 of ring 151 andshoulder 131, the other such pinch point being between trailing end 155of ring 151 and leading end 143 of ring 141. The outer diameter of outerring 151 is preferably not much greater than the outer diameters ofshoulder 131 and inner ring 141, respectively, so that the exterior ofassembly 101 is substantially uniform over the region extending fromthat portion of tube 103 covering shoulder 131 to that portion of tube103 covering inner ring 141.

Although the inner surface 159 of outer ring 151 is shown in the presentembodiment as a straight surface, it can readily be appreciated thatinner surface 159 could be chamfered at leading end 153 and/or trailingend 155 to facilitate the insertion of tube 103 through bore 157.

Assembly 101 preferably further comprises a hypotube 161, hypotube 161being a unitary tubular member coaxially disposed within bore 126towards the trailing end thereof to provide reinforcement to trailingend 125 of fitting 121 against damage caused by bending. Hypotube 161 ispreferably made of stainless steel, and fitting 121 may be insert-moldedaround hypotube 161.

Assembly 101 has been tested by the present inventors, and theconnection of dilator 108 to tube 103 therein has been found to meet theindustry standard minimum tensile strength of 17 pounds.

To assemble assembly 101, inner ring 141 is inserted into tube 103through leading end 107, preferably to a depth of about 1.5 inches.Next, leading end 107 of tube 103 is inserted through outer ring 151until outer ring 151 is positioned just before inner ring 141. Next,rear portion 122-3 of fitting 121 is inserted through leading end 107 oftube 103 and into longitudinal bore 146 of inner ring 141. Fitting 121and inner ring 141 are then screwed tightly together, causing tube 103to be pinched between outer ring 151 and shoulder 131 and between outerring 151 and inner ring 141. (If desired, a drop of medical grade gluemay be placed at about the midsection of rear portion 122-2 prior toinsertion of fitting 121 into tube 103 in order to strengthen theconnection between fitting 121 and inner ring 141.) With fitting 121 andinner ring 141 thus screwed together, leading end 107 of tube 103becomes tucked into the recessed area between shoulder 131 and barbs127. Lastly, front portion 122-1 of fitting 121 is inserted into dilator108 through trailing end 111, whereby barbs 127 of fitting 121 engagethe inner surface of dilator 108 to retain fitting 121 therewithin. Onceassembled, assembly 101 may be used in the same fashion as assembly 11.

As can readily be appreciated, the aforementioned assembly steps may beperformed manually or may be automated to varying degrees.

In the present embodiment, each of fitting 121, inner ring 141 and outerring 151 is preferably made of the same material, namely, a moldedplastic, such as acetal. However, it can readily be appreciated thatfitting 121, inner ring 141 and outer ring 151 need not be made of thesame material and, in fact, need not even be made of molded plastic. Forexample, one or more of fitting 121, inner ring 141 and outer ring 151could be made of stainless steel although the material costs and/or thefabrication costs (e.g., machining) would likely be greater forstainless steel than for molded plastic.

It should also be noted that, if one were to make fitting 121 anddilator 108 of the same material, such as polyethylene, one could omitbarbs 127 from fitting 121 and then join fitting 121 to dilator 108 byspin-welding. (In such a case, the leading portion of fitting 121 wouldpreferably have a conical or frustoconical shape to accommodatespin-welding.)

Similarly, provided that fitting 121 and inner ring 141 are made of thesame material, fitting 121 and inner ring 141 may be joined together byspin-welding. (In such a case, threads 129 and 147 would preferably beomitted from fitting 121 and inner ring 141, respectively, and rearportion 122-3 of fitting 121 would preferably have a conical orfrustoconical shape.)

It should also be noted that, although fitting 121 is disclosed in thepresent embodiment as a unitary structure, one could assemble fitting121 from two or more separate pieces.

Referring now to FIG. 9, there is shown a fragmentary, section view of asecond embodiment of a medical catheter assembly constructed accordingto teachings of the present invention, said medical catheter assemblybeing adapted for percutaneous endoscopic use in a patient using thepush method and being represented generally by reference numeral 201.

Assembly 201 is similar in certain respects to assembly 101, theprincipal differences between the two assemblies being that assembly 201does not include fitting 121 and inner ring 141, but instead, includes afitting 203 and an inner ring 205, respectively. In addition, assembly201 differs from assembly 101 in that assembly 201 does not includehypotube 161.

Fitting 203, which is shown separately in FIGS. 10( a) and 10(b), issimilar in many respects to fitting 121, the principal differencebetween the two fittings being that fitting 203 includes a rear portion207, instead of rear portion 122-3. Rear portion 207 comprises a pair ofparallel legs 209-1 and 209-2, legs 209-1 and 209-2 having front ends211-1 and 211-2, respectively, that are fixed to shoulder 131 and rearends 213-1 and 213-2, respectively, that are adapted to be resilientlyflexed towards one another. Rear ends 213-1 and 213-2 are shaped toinclude outwardly opposed feet 215-1 and 215-2, respectively, thepurpose of which will become apparent below.

Inner ring 205, which is shown separately in FIGS. 11( a) and 11(b), issimilar in many respects to inner ring 141, the principal differencebetween the two rings being that inner ring 205 does not include aninternal helical thread 147, but rather, includes a pair of transverseopenings 217-1 and 217-2, openings 217-1 and 217-2 being appropriatelysized and positioned on ring 205 to receive feet 215-1 and 215-2,respectively.

Assembly 201 is assembled in much the same fashion as assembly 101, theprincipal difference between the two assemblies being that, withassembly 201, fitting 203 and inner ring 205 are coupled together by asnap-fit by inserting fitting 203 into inner ring 205 until that feet215-1 and 215-2 are received in openings 217-1 and 217-2, respectively.Once assembled, assembly 201 is used in the same fashion as assembly101.

Referring now to FIGS. 12( a) and 12(b), there are shown fragmentary,longitudinal section and transverse section views, respectively, of athird embodiment of a medical catheter assembly constructed according toteachings of the present invention, said medical catheter assembly beingadapted for percutaneous endoscopic use in a patient using the pushmethod and being represented generally by reference numeral 301.

Assembly 301 is similar in certain respects to assembly 101, theprincipal differences between the two assemblies being that assembly 301does not include fitting 121 and inner ring 141, but instead, includes afitting 303 and an inner ring 305, respectively. In addition, assembly301 differs from assembly 101 in that assembly 301 does not includehypotube 161.

Fitting 303, which is shown separately in FIGS. 13( a) and 13(b), issimilar in many respects to fitting 121, the principal differencebetween the two fittings being that fitting 303 includes a rear portion307, instead of rear portion 122-3. Rear portion 307 is generallytubular and is shaped to include a slot 311, slot 311 extendinglongitudinally forward a short distance from the rear end of rearportion 307 to define a pair of trailing end sections 312-1 and 312-2. Afirst L-shaped recess is provided in trailing end section 312-1, and asecond L-shaped recess is provided in trailing end section 312-2. TheseL-shaped recesses, which are spaced 180 degrees apart along thecircumference of rear portion 307, include circumferentially-extendingportions 315-1 and 315-2, respectively, and longitudinally-extendingportions 317-1 and 317-2, respectively. Each ofcircumferentially-extending portions 315-1 and 315-2 communicate at oneend thereof with the forward end of slot 311, and each oflongitudinally-extending portions 317-1 and 317-2 extend rearwardly ashort distance.

Inner ring 305, which is shown separately in FIG. 14, is similar in manyrespects to inner ring 141, the principal difference between the tworings being that inner ring 305 does not include an internal helicalthread 147, but rather, includes a pair of rectangular blocks 321-1 and321-2 projecting radially inwardly a short distance from the innersurface of inner ring 305 at its leading end 323. Blocks 321-1 and 321-2are appropriately sized and spaced apart on ring 305 so as to permittheir insertion through slot 311 and into recesses 313-1 and 313-2,respectively.

Assembly 301 is assembled in much the same fashion as assembly 101, theprincipal difference between the two assemblies being that, withassembly 301, fitting 303 and inner ring 305 are coupled togetherthrough a U-lock by inserting fitting 303 into inner ring 305 untilblocks 321-1 and 321-2 are advanced to the front end of slot 311, thentwisting fitting 303 relative to inner ring 305 as far as possible todraw blocks 321-1 and 321-2 fully through circumferentially-extendingportions 315-1 and 315-2, respectively, of recesses 313-1 and 313-2,respectively, and then pulling fitting 303 away from inner ring 305 asfar as possible to draw blocks 321-1 and 321-2 fully throughlongitudinally-extending portions 317-1 and 317-2, respectively, ofrecesses 313-1 and 313-2. Once assembled, assembly 301 is used in thesame fashion as assembly 101.

Referring now to FIGS. 15 and 16, there are shown fragmentary, sectionand partially-exploded, perspective views, respectively, of a fourthembodiment of a medical catheter assembly constructed according toteachings of the present invention, said medical catheter assembly beingadapted for percutaneous endoscopic use in a patient using the pullmethod and being represented generally by reference numeral 401.

Assembly 401 comprises a gastrostomy feeding tube 403 and an internalbolster 404, tube 403 and bolster 404 being identical to tube 103 andbolster 104 of assembly 101.

Assembly 401 additionally comprises a fitting assembly 405, fittingassembly 405 comprising a fitting 407. Fitting 407, which is made of arigid plastic, is shaped to include a front portion 409, an intermediateportion 411, and a rear portion 413. Front portion 409, which serves asa dilator, is conical in shape and tapers in diameter from its rear end415 to a front tip 417. A wire loop 419, which is adapted to be securedto the first end of a suture, is fixed, preferably by insert-molding, tofront tip 417.

Intermediate portion 411, which is cylindrical in shape and coaxial withfront portion 409, is appropriately sized to snugly receive thereoverthe leading end 421 of tube 403 by a press-fit and, at the same time,hold leading end 421 of tube 403 so that it lies flush with rear end 415of front portion 409.

Rear portion 413, which is cylindrical in shape and coaxial withintermediate portion 411, has a reduced diameter as compared tointermediate portion 411. An external helical thread 423, the purpose ofwhich will become apparent below, is formed along the length of rearportion 413.

Assembly 401 further comprises an inner ring 441, inner ring 441 beingsimilar to inner ring 141 of assembly 101. As such, inner ring 441 is aunitary tubular member preferably made of a rigid material, such as arigid molded plastic, and has a leading end 443, a trailing end 445 anda longitudinal bore 446. Inner ring 441 is coaxially positioned withintube 403 at a certain depth, e.g., about 1.5 inches from leading end421, and has an outer diameter that is greater than the inner diameterof tube 403; as a result, inner ring 441 is secured within tube 403 by apress-fit.

Longitudinal bore 446 of inner ring 441 is appropriately sized toreceive rear portion 413 of fitting 407 therewithin, and an internalhelical thread 447 is formed on the inner surface of inner ring 441 tomatingly engage external helical thread 423 so as to lock togetherfitting 407 and ring 441.

Assembly 401 further comprises an outer ring 451, outer ring 451 beingsimilar to outer ring 151 of assembly 101. As such, outer ring 451 is aunitary tubular member preferably made of a rigid material, such as arigid molded plastic, and has a leading end 453, a trailing end 455 anda longitudinal bore 457. Outer ring 451 coaxially surrounds tube 403between intermediate portion 411 of fitting 407 and inner ring 441 andhas an inner diameter that is both slightly greater than rear portion413 of fitting 407 and less than the outer diameters of intermediateportion 411 and inner ring 441, respectively. In this manner, withfitting 407 and ring 441 fully screwed together, tube 403 becomessecurely coupled to fitting 407 through a pair of pinch points, one suchpinch point being between leading end 453 of ring 451 and the rear endof intermediate portion 411 (the rear end of intermediate portion 411functioning analogously to shoulder 131 of assembly 101), the other suchpinch point being between trailing end 455 of ring 451 and leading end443 of ring 441. The outer diameter of outer ring 451 is preferably notmuch greater than the outer diameters of intermediate portion 411 andinner ring 441, respectively, so that the exterior of assembly 401 issubstantially uniform in diameter over the region extending from thatportion of tube 403 covering intermediate portion 411 to that portion oftube 403 covering inner ring 441.

To assemble assembly 401, inner ring 441 is inserted into tube 403through leading end 421, preferably to a depth of about 1.5 inches.Next, leading end 421 of tube 403 is inserted through outer ring 451until outer ring 451 is positioned just before inner ring 441. Next,rear portion 413 of fitting 407 is inserted through leading end 421 oftube 403 and into longitudinal bore 446 of inner ring 441. Fitting 407and inner ring 441 are then screwed tightly together, causing leadingend 421 of tube 403 to be drawn over intermediate portion 411 andcausing tube 403 to be pinched between outer ring 451 and intermediateportion 411 and between outer ring 451 and inner ring 441. (If desired,a drop of medical grade glue may be placed at about the midsection ofrear portion 413 prior to insertion of fitting 407 into tube 403 inorder to strengthen the connection between fitting 407 and inner ring441.) Once assembled, assembly 401 may be used in the same fashion asassembly 71.

It should be noted that, although the assemblies of the presentinvention have been described in the context of implanting tubes as partof percutaneous endoscopic gastrostomies, the present assemblies couldalso be used to implant catheters as part of any number of other medicalprocedures including, but not limited to, percutaneous endoscopicjejunostomies. Moreover, the connectors used in the push-type medicalcatheter assemblies described herein are not limited to use in catheterimplanting assemblies and may be used to join together various types oftubing for a wide variety of different applications.

The embodiments of the present invention described above are intended tobe merely exemplary and those skilled in the art shall be able to makenumerous variations and modifications to it without departing from thespirit of the present invention. For example, although specificmechanical arrangements are disclosed herein for coupling together thefitting and inner ring components of the connector, other arrangementscould easily be devised. All such variations and modifications areintended to be within the scope of the present invention as defined inthe appended claims.

1. A medical catheter assembly comprising: (a) a medical catheter; (b) afirst tubular member, said first tubular member being secured withinsaid medical catheter; (c) a fitting, said fitting comprising a shoulderand a rear portion, said rear portion being positioned within said firsttubular member and secured thereto, said shoulder being positioned infront of said rear portion; and (d) a second tubular member, said secondtubular member being inserted over said medical catheter and positionedbetween said shoulder and said first tubular member, said second tubularmember being appropriately sized to securely retain said medicalcatheter between said second tubular member and said first tubularmember and to securely retain said medical catheter between said secondtubular member and said shoulder.
 2. The medical catheter assembly asclaimed in claim 1 wherein said medical catheter surrounds saidshoulder.
 3. A medical catheter assembly comprising: (a) a medicalcatheter, said medical catheter being made of an elastic material andhaving a front end, a rear end and an inner diameter; (b) a firsttubular member, said first tubular member having an outer diametergreater than the inner diameter of said medical catheter, said firsttubular member being coaxially disposed within said medical catheter andsecured thereto by a friction-fit; (c) a fitting, said fittingcomprising a shoulder and a rear portion, said shoulder being positionedin front of said rear portion and having an outer diameter greater thanthe inner diameter of said medical catheter, said shoulder and said rearportion being inserted into said medical catheter through said frontend, with said rear portion inserted into said first tubular member andsecured thereto; and (d) a second tubular member, said second tubularmember being inserted over said medical catheter and positioned betweensaid shoulder and said first tubular member, said second tubular memberbeing appropriately sized to securely retain said medical catheterbetween said second tubular member and said first tubular member and tosecurely retain said medical catheter between said second tubular memberand said shoulder.
 4. The medical catheter assembly as claimed in claim3 wherein said first tubular member is provided with an internal thread,wherein said rear portion of said fitting is provided with an externalthread and wherein said first tubular member and said rear portion ofsaid fitting are secured to one another by threaded engagement of saidinternal thread and said external thread.
 5. The medical catheterassembly as claimed in claim 3 wherein said first tubular member isprovided with a transverse opening, wherein said rear portion of saidfitting is provided with a resilient leg, said resilient leg having afoot adapted for insertion through said transverse opening and whereinsaid first tubular member and said rear portion of said fitting aresecured to one another by insertion of said foot through said transverseopening.
 6. The medical catheter assembly as claimed in claim 3 whereinsaid first tubular member is provided with a pair of transverseopenings, wherein said rear portion of said fitting is provided with apair of resilient legs, each of said resilient legs having a footadapted for insertion through one of said transverse openings andwherein said first tubular member and said rear portion of said fittingare secured to one another by insertion of said feet through saidtransverse openings.
 7. The medical catheter assembly as claimed inclaim 3 wherein said first tubular member is provided with a projectionextending radially inwardly, wherein said rear portion of said fittingis provided with a recess adapted to receive said projection and whereinsaid first tubular member and said rear portion of said fitting aresecured to one another by insertion of said projection into said recess.8. The medical catheter assembly as claimed in claim 3 wherein saidfirst tubular member is provided with a pair of opposing projectionsextending radially inwardly, wherein said rear portion of said fittingis provided with a slot and a pair of L-shaped recesses, said slotextending longitudinally from a rear end of said rear portion of saidfitting and adapted for insertion of said pair of opposing projectionstherethrough, one of said L-shaped recesses being adapted to receive oneof said pair of opposing projections, the other of said L-shapedrecesses being adapted to receive the other of said pair of opposingprojections, each of said L-shaped recesses having acircumferentially-extending section communicating with said slot and alongitudinally-extending section extending towards said first end, andwherein said first tubular member and said rear portion of said fittingare secured to one another by inserting said projections through saidslot, through said circumferentially-extending sections of said L-shapedrecesses and into said longitudinally-extending sections of saidL-shaped recesses.
 9. The medical catheter assembly as claimed in claim3 wherein said first tubular member and said rear portion of saidfitting are secured to one another by spin-welding.
 10. The medicalcatheter assembly as claimed in claim 3 wherein said medical catheter isa silicone tube.
 11. The medical catheter assembly as claimed in claim 3wherein said fitting further has a front portion in front of saidshoulder, said front portion extending beyond said front end of saidmedical catheter, said front portion of said fitting being conical inshape and coming to a tip at a front end of said fitting.
 12. Themedical catheter assembly as claimed in claim 11 further comprising awire loop, said wire loop extending forwardly from said front end ofsaid fitting.
 13. The medical catheter assembly as claimed in claim 3wherein said fitting further has a front portion in front of saidshoulder, said front portion of said fitting extending beyond saidmedical catheter and shaped to include at least one barb.
 14. Themedical catheter assembly as claimed in claim 13 wherein said frontportion of said fitting is shaped to include a plurality of barbs. 15.The medical catheter assembly as claimed in claim 13 wherein saidfitting is provided with a longitudinal bore.
 16. The medical catheterassembly as claimed in claim 3 wherein said fitting further comprises aclosed front portion in front of said shoulder, said medical catheterassembly further comprising a length of tubing, said length of tubingcomprising a front end and a rear end, said front portion of saidfitting being inserted into said length of tubing through said rear endthereof and secured within said length of tubing.
 17. The medicalcatheter assembly as claimed in claim 16 wherein said front portion ofsaid fitting is shaped to include at least one barb for securing saidfront portion of said fitting within said length of tubing.
 18. Themedical catheter assembly as claimed in claim 16 wherein said medicalcatheter is a feeding tube and wherein said length of tubing is adilator.
 19. The medical catheter assembly as claimed in claim 18wherein said dilator has an outwardly flared rear end.
 20. The medicalcatheter assembly as claimed in claim 18 further comprising an internalbolster, said internal bolster being disposed at said rear end of saidfeeding tube.
 21. A medical catheter assembly comprising: (a) a medicalcatheter, said medical catheter being made of an elastic material andhaving a front end, a rear end and an inner diameter; (b) a firsttubular member, said first tubular member having an outer diametergreater than an inner diameter of said medical catheter, said firsttubular member being coaxially disposed within said medical catheter andsecured thereto by a friction-fit; (c) a fitting, said fittingcomprising a front portion, a shoulder and a rear portion, said shoulderbeing positioned between said front portion and said rear portion andhaving an outer diameter greater than the inner diameter of said medicalcatheter, said shoulder and said rear portion being inserted into saidmedical catheter through a front end of said medical catheter, with saidrear portion inserted into said first tubular member and securedthereto; (d) a second tubular member, said second tubular member beinginserted over said medical catheter and positioned between said shoulderand said first tubular member, said second tubular member beingappropriately sized to securely retain said medical catheter betweensaid second tubular member and said first tubular member and to securelyretain said medical catheter between said second tubular member and saidshoulder; and (e) a length of tubing, said length of tubing having afront end and a rear end, said front end of said fitting being insertedinto said length of tubing through said rear end thereof and securedwithin said length of tubing.
 22. The medical catheter assembly asclaimed in claim 21 wherein said front portion of said fitting is shapedto include at least one barb for securing said front portion of saidfitting within said length of tubing.
 23. The medical catheter assemblyas claimed in claim 21 wherein said medical catheter is a feeding tubeand wherein said length of tubing is a dilator.
 24. The medical catheterassembly as claimed in claim 23 further comprising an internal bolster,said internal bolster being disposed at said rear end of said feedingtube.
 25. The medical catheter assembly as claimed in claim 21 whereinsaid fitting further comprises a longitudinal bore.
 26. A connector forconnecting a first length of tubing to a second length of tubing, thefirst length of tubing being made of an elastic material, said connectorcomprising: (a) a first tubular member, said first tubular member havingan outer diameter greater than the inner diameter of said first lengthof tubing, said first tubular member being adapted to be coaxiallyinserted into said first length of tubing and secured therewithin by afriction-fit; (b) a fitting, said fitting comprising a front portion, ashoulder and a rear portion, said shoulder being positioned between saidfront portion and said rear portion and having an outer diameter greaterthan the inner diameter of said first length of tubing, said shoulderand said rear portion being adapted to be coaxially inserted into saidfirst length of tubing, said rear portion of said fitting being adaptedto be coaxially inserted into said first tubular member and securedthereto, said front portion of said fitting being adapted to becoaxially inserted into said second length of tubing and securedthereto; and (c) a second tubular member, said second tubular memberbeing adapted to be inserted over said first length of tubing andpositioned between said shoulder and said first tubular member, saidsecond tubular member being appropriately sized so that, with saidfitting and said first tubular member secured to one another, said firstlength of tubing may be securely retained between said second tubularmember and said first tubular member and between said second tubularmember and said shoulder.
 27. A connector for use with a first length oftubing, the first length of tubing being made of an elastic material,said connector comprising: (a) a first tubular member, said firsttubular member having an outer diameter greater than the inner diameterof said first length of tubing, said first tubular member being adaptedto be coaxially inserted into said first length of tubing and securedtherewithin by a friction-fit; (b) a fitting, said fitting comprising afront portion, a shoulder and a rear portion, said shoulder beingpositioned between said front portion and said rear portion and havingan outer diameter greater than the inner diameter of said first lengthof tubing, said shoulder and said rear portion being adapted to becoaxially inserted into said first length of tubing, with said rearportion of said fitting being adapted to be coaxially inserted into saidfirst tubular member and secured thereto, said front portion of saidfitting being conical in shape and terminating in a tip at a front endthereof; (c) a wire loop extending forwardly from said front end of saidfitting; and(d) a second tubular member, said second tubular memberbeing adapted to be inserted over said first length of tubing andpositioned between said shoulder and said first tubular member, saidsecond tubular member being appropriately sized so that, with saidfitting and said first tubular member secured to one another, said firstlength of tubing may be securely retained between said second tubularmember and said first tubular member and between said second tubularmember and said shoulder.
 28. The medical catheter assembly as claimedin claim 1 wherein said second tubular member forms a first pinch pointin the medical catheter between said second tubular member and saidfirst tubular member, and forms a second pinch point in the medicalcatheter between said second tubular member and said shoulder.